Firefighters are battling strong winds and the potential for triple-digit temperatures as they try to contain separate wildfires in Utah and California. In Utah, more than a thousand firefighters are still struggling to contain a huge fire that started on June 17 near Brian Head, a ski town. In Santa Clarita, Calif., north of Los Angeles, those who had been evacuated are now being allowed to return to their homes, and an official said on Monday that the fire was almost under control.

The Brian Head fire is 10 percent contained and had burned more than 43,000 acres, officials said on Monday. No injuries were reported and more than a dozen residential buildings were damaged. Roughly 1,500 residents have been evacuated since the fire started. Some residents are being allowed to return to their homes with escorts. As of Monday, the area remained under a warning from the National Weather Service that “gusty winds and low humidities will combine to cause critical fire weather conditions this afternoon.”

The Santa Clarita fire, which started on Sunday on the 14 Freeway after a vehicle rolled over onto dry brush, had burned 870 acres as of Monday, according to Christopher Craft, an official with the Santa Clarita fire department. He said that one nonresidential structure had burned. The freeway has reopened and the fire is 57 percent under control, he said on Monday afternoon. One deputy was treated for smoke inhalation on Sunday night. The driver of the car, an 80-year-old woman, sustained moderate injuries and transported to a hospital. Mr. Craft said the fire should be completely contained within a day.

A version of this article appears in print on , Section A, Page 17 of the New York edition with the headline: Firefighters Battle Wildfires in California and Utah. Order Reprints | Today’s Paper | Subscribe